CN102355136B - Control method and control circuit for controlling output current of converter - Google Patents

Control method and control circuit for controlling output current of converter Download PDF

Info

Publication number
CN102355136B
CN102355136B CN 201110295481 CN201110295481A CN102355136B CN 102355136 B CN102355136 B CN 102355136B CN 201110295481 CN201110295481 CN 201110295481 CN 201110295481 A CN201110295481 A CN 201110295481A CN 102355136 B CN102355136 B CN 102355136B
Authority
CN
China
Prior art keywords
signal
current
gate
controlled switch
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN 201110295481
Other languages
Chinese (zh)
Other versions
CN102355136A (en
Inventor
张军明
曾鹄龙
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Original Assignee
Zhejiang University ZJU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU filed Critical Zhejiang University ZJU
Priority to CN 201110295481 priority Critical patent/CN102355136B/en
Publication of CN102355136A publication Critical patent/CN102355136A/en
Application granted granted Critical
Publication of CN102355136B publication Critical patent/CN102355136B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Abstract

The invention discloses a control circuit and method for controlling the output current of a converter, which is suitable for all types of isolated or non-isolated converters. According to the method disclosed by the invention, by collecting the current signal of a controllable switch, the voltage signal in the converter and a control signal on the controllable switch at a certain time, and acquiring the reference voltage signal, the average current signal, the diode turn-on time signal and the controllable switch turn-on time signal are derived by calculation, comparison, detection, modulation and the like, and a control signal for controlling the controllable switch to be turned on or turned off is generated, thus controlling the output current of the converter and being applicable to all kinds of control modes. In addition, according to the invention, the information of output current can be acquired based on the signal of the controllable switch output end and the voltage signal in the converter, thereby realizing indirect control of the output current, reducing sampling the current of the converter, simplifying the circuit structure, reducing circuit loss and saving the cost of the circuit composition.

Description

A kind of control method of controlling the current transformer output current
Technical field
The present invention relates to power circuit, particularly a kind of control method and control circuit thereof of controlling the current transformer output current.
Background technology
Traditional in traditional small power electric source device, especially small-power switching power-supply, the charger that is used for portable set, charger as charger for mobile phone, notebook adapter, mobile unit, and the driving power of small power LED illumination, comprise led driver or LED, it is constant or adjustable that its power circuit need be controlled output current usually; Traditional control mode is regulated with ON time or the frequency of gate-controlled switch in the feedback circuit control power circuit then for output current is sampled.
In the isolated form current transformer, use transformer to realize electrical isolation usually; Because output current detection circuit makes control circuit usually at the input of main circuit at the output of main circuit but gate-controlled switch is positioned at the former limit of transformer, this feedback loop that causes output current is in requisition for electrical isolation; The light-coupled isolation of generally selecting for use in the prior art is: the error signal of output current feedback is imported control circuit on the former limit through optocoupler, to control the operating state of gate-controlled switch on the former limit.
Traditional isolated form inverse-excitation type current transformer as shown in Figure 1 and the control circuit of output current thereof comprise feedback circuit W and integrated circuit A, and feedback circuit W is positioned at the output of circuit of reversed excitation, and integrated circuit A is positioned at the input of circuit of reversed excitation; Described feedback circuit W gathers the current signal Iload of current output terminal, the reference voltage signal Vref that current signal Iload and reference voltage source U are provided compares, produce an error signal Vea, error signal Vea is transferred to integrated circuit A through light-coupled isolation, be used for controlling the operating state of gate-controlled switch Q on the former limit, realize the closed-loop control of circuit of reversed excitation output current.This method is complex circuit not only, and because the current signal Iload that gathers output causes increasing circuit loss, and the existence of optocoupler is unfavorable to electric insulation, is easy to generate leakage current, has reduced the reliability of power circuit.
In the non-isolation type current transformer, although input and output do not need electrical isolation, because the current signal of collection output and control circuit are not altogether, cause the voltage reference points of the two different, the problem that exists signal to isolate equally.BUCK-BOOST current transformer as shown in Figure 2 and the control circuit of output current thereof, the BUCK-BOOST current transformer is non-isolation type inverse-excitation type current transformer, drive gate-controlled switch Q for convenience, generally gate-controlled switch Q is connected on the ground wire of input, this causes the reference potential of the current signal Iload of the output that control circuit gathers and control circuit inconsistent.In order to overcome this defective, often use the sample circuit of difference channel or isolation in the practical operation, as Hall element, current transformer etc., with current signal Iload process foregoing circuit input control circuit.But the common price of above-mentioned difference channel or sample circuit is higher, and shortcomings such as can not being suitable for the high frequency occasion is arranged, and uses the back to have the problem identical with the isolated form current transformer, and is difficult as the output current signal sampling, need isolate etc.
Equally, a kind of non-isolation type BUCK class current transformer as shown in Figure 3 and the control circuit of output current thereof drive gate-controlled switch Q for convenience, also gate-controlled switch Q are connected on the ground wire of input usually.Obviously, the output end current signal of collection and the reference potential of control circuit are inconsistent, have similar problem with the control circuit of BUCK-BOOST current transformer output current.
Except the feedback control circuit of above-mentioned output current, the control circuit of Direct Sampling output current does not obtain use to a certain degree yet, in the isolated form current transformer, carry out the FEEDBACK CONTROL of output current based on the current signal of transformer input, but this control circuit generally is only applicable to discontinuous current mode of operation (DCM) and electric current critical discontinuous mode (CRM), be not suitable for continuous current mode (CCM), circuit structure is also very complicated.
Publication number is that the adaptive output current that the Chinese patent of CN101242143 discloses a kind of switching circuit on August 13rd, 2008 is controlled, and this switching circuit has input circuit and the output circuit of electric insulation each other; Output current value can be based on output voltage, and output circuit and expression are determined corresponding to the reflection output voltage of the voltage in the input circuit of output voltage; Switch element in the input circuit is controlled to the determined value that produces output current; Have following problems: the output current computing formula under CCM and DCM mode of operation is inconsistent, makes that the circuit under the different current working modes can't be unified; Computing formula under the DCM mode of operation has been used evolution calculating, makes to realize comparatively complexity.
Summary of the invention
Aforesaid for solving, the output current control circuit complexity that exists in the isolated form current transformer, loss are big, poor insulativity and easily produce problem such as leakage current, the inconsistent technical barrier that causes of the output current reference potential because of output current control circuit and gate-controlled switch that in non-isolation type current transformer such as BUCK-BOOST current transformer and BUCK class current transformer, exists, the invention provides a kind of control method and the control circuit thereof that can control the current transformer output current, when being applicable to DCM mode of operation and CRM mode of operation, also be applicable to the CCM mode of operation.
A kind of control method of controlling the current transformer output current may further comprise the steps:
(1) obtain reference voltage signal, and gather current signal and last a control signal constantly of gate-controlled switch in the current transformer, and the voltage signal in the current transformer;
(2) the switching frequency component in the described gate-controlled switch current signal of filtering obtains average current signal;
(3) described voltage signal is changed, obtained voltage instruction signal, then described voltage instruction signal is detected, obtain the diode current flow time signal;
(4) based on the control signal in a moment on the gate-controlled switch, obtain gate-controlled switch ON time signal;
(5) based on described average current signal, diode current flow time signal and gate-controlled switch ON time signal, calculate output current signal; Described output current signal and described reference voltage signal are compared, obtain error signal;
The formula that calculates output current signal is:
In the inverse-excitation type current transformer be:
Io=Iavg*Ton_s/Ton_p;
In BUCK class current transformer be:
Io=Iavg*(Ton_s+Ton_p)/Ton_p;
Wherein, Io is output current signal, and Iavg is average current signal, and Ton_s is the diode current flow time signal, and Ton_p is gate-controlled switch ON time signal.
(6) described error signal is modulated the control signal that obtains the gate-controlled switch current time, with conducting or the shutoff of gate-controlled switch in the control current transformer; Described modulation is modulated to the best with PWM.
In the described step (1), can carry out the control of cut angle to the AC signal of current transformer, and obtain reference voltage signal through modulation.
In the described step (3), the process that voltage instruction signal is detected is: earlier described voltage instruction signal is carried out zero passage detection, obtain the zero current detection signal; Then described zero current detection signal is carried out pulsewidth and detect, obtain the diode current flow time signal.
In the described step (4), the control signal in a moment on the gate-controlled switch is carried out pulsewidth detect, obtain gate-controlled switch ON time signal.
A kind of control circuit of controlling the current transformer output current comprises:
Low pass filter is used for receiving the current signal of current transformer gate-controlled switch, and exports average current signal; Described low pass filter can be the RC filter;
Voltage sampling circuit, for the voltage signal of gathering current transformer, and the output voltage index signal; Described voltage sampling circuit: at the isolated form current transformer, in isolated form inverse-excitation type current transformer, be auxiliary winding or the differential circuit of anti-violent change depressor in the current transformer; At the non-isolation type current transformer, in BUCK-BOOST current transformer and non-isolation type BUCK class current transformer, be the coupling winding of inductance in the current transformer;
The diode current flow time detection circuit is used for receiving described voltage instruction signal, and output diode ON time signal; Described diode current flow time detection circuit comprises:
Zero cross detection circuit is used for receiving described voltage instruction signal, output zero current detection signal;
Pulse width detection circuit is used for receiving described zero current detection signal, output diode ON time signal;
Gate-controlled switch ON time testing circuit is used for receiving the control signal in a moment on the gate-controlled switch, and exports gate-controlled switch ON time signal;
Computing circuit is used for receiving described average current signal, diode current flow time signal and gate-controlled switch ON time signal, and produces output current signal; Described computing circuit can be multiplier;
Reference voltage source is used for providing reference voltage signal;
Error compensation circuit is used for receiving described reference voltage signal and described output current signal, and output error signal;
Modulation circuit is used for receiving described error signal, and the control end that controls signal to gate-controlled switch of output gate-controlled switch current time; Described modulation circuit can be the PWM modulation circuit.
The present invention is by gathering the current signal of gate-controlled switch, the control signal in a moment on voltage signal in the current transformer and the gate-controlled switch, and obtain the reference voltage signal that reference voltage source provides, as calculated, relatively, processing such as detection and modulation, draw average current signal, diode current flow time signal and gate-controlled switch ON time signal, produce the control signal of the gate-controlled switch current time of control gate-controlled switch conducting or shutoff, to reach the effect of control current transformer output current, can be applied to various control modes, as frequency conversion rate control (VF, variable frequency), fixed control mode (CF, constant frequency) frequently; And, the present invention is based on the signal of gate-controlled switch output and the information that the voltage signal in the current transformer can obtain output current, realize the indirect control of output current, minimizing is to the current sample of current transformer, not only simplify circuit structure, reduced circuit loss, also saved the cost that circuit is formed.
Description of drawings
Fig. 1 is a kind of structural representation of controlling the control circuit of its output current in a kind of isolated form inverse-excitation type current transformer and the prior art.
Fig. 2 is a kind of structural representation of controlling the control circuit of its output current in a kind of BUCK-BOOST current transformer and the prior art.
Fig. 3 is a kind of structural representation of controlling the control circuit of its output current in a kind of non-isolation type BUCK class current transformer and the prior art.
Fig. 4 is a kind of schematic flow sheet of controlling the method for current transformer output current of the present invention.
The structural representation of a kind of control circuit that Fig. 5 controls its output current for isolated form inverse-excitation type current transformer shown in Figure 1 and the present invention.
Fig. 6 is the internal structure block diagram of control circuit A among Fig. 5.
Fig. 7 is the electrical block diagram of RC filter A1 among Fig. 6.
Fig. 8 is the working waveform figure of Fig. 5 circuit.
Fig. 9 is a kind of structural representation of diode current flow time detection circuit A2 among Fig. 6.
Figure 10 removes the structural representation of rest-set flip-flop F for diode current flow time detection circuit A2 among Fig. 9.
Figure 11 is a kind of structural representation of gate-controlled switch ON time testing circuit A3 among Fig. 6.
Figure 12 is a kind of structural representation of error compensation circuit A5 among Fig. 6.
Figure 13 is a kind of structural representation of pulse-width modulation circuit A6 among Fig. 6.
Figure 14 is a kind of structural representation of realizing diode current flow time detection circuit A2 among Fig. 6 with digital form.
Figure 15 removes the structural representation of rest-set flip-flop F for diode current flow time detection circuit A2 among Figure 14.
Figure 16 is a kind of structural representation of realizing gate-controlled switch ON time testing circuit A3 among Fig. 6 with digital form.
The structural representation of a kind of control circuit with differential circuit that Figure 17 controls its output current for isolated form inverse-excitation type current transformer shown in Figure 1 and the present invention.
Figure 18 is the working waveform figure of circuit shown in Figure 17.
The structural representation of a kind of control circuit that Figure 19 controls its output current for BUCK-BOOST current transformer shown in Figure 2 and the present invention.
The structural representation that Figure 20 controls a kind of control circuit of its output current for non-isolation type BUCK class current transformer shown in Figure 3 and the present invention.
Figure 21 is the internal structure block diagram of control circuit A among Figure 20.
Figure 22 is the working waveform figure of circuit shown in Figure 20.
Figure 23 is a kind of isolated form current transformer of the TRIAC of containing light adjusting circuit and the structural representation of a kind of control circuit that the present invention controls its output current.
Figure 24 is a kind of structural representation of reference voltage source U.
Figure 25 is the input voltage waveform figure of TRIAC light adjusting circuit.
Figure 26 implements schematic diagram for a kind of circuit of PWM modulation.
Embodiment
Introduce the specific embodiment of the present invention in detail below in conjunction with accompanying drawing, yet, should be understood that principle of the present invention has the power circuit of corresponding relation all to be suitable for to any gate-controlled switch electric current and output current.
A kind of control method of controlling the current transformer output current as shown in Figure 4 may further comprise the steps:
The control signal in a moment on the current signal of gate-controlled switch, the voltage signal in the current transformer, the gate-controlled switch in the S1 collection current transformer, and obtain reference voltage signal;
Switching frequency component in the S2 filtering gate-controlled switch current signal obtains average current signal;
S3 is, and voltage signal is changed, and obtains voltage instruction signal; Voltage instruction signal is detected, obtain the diode current flow time signal;
Among the S3, voltage instruction signal detected comprise the steps:
The voltage instruction signal of S31 carries out zero passage detection, obtains the zero current detection signal;
The zero current detection signal of S32 carries out pulsewidth and detects, and obtains the diode current flow time signal;
The control signal in a moment is carried out the pulsewidth detection on the gate-controlled switch of S4, obtains gate-controlled switch ON time signal;
Among the S5, S51 calculates output current signal based on average current signal, diode current flow time signal and gate-controlled switch ON time signal;
Wherein, the formula of calculating output current signal is:
S511 in the inverse-excitation type current transformer is:
Io=Iavg*Ton_s/Ton_p;
S512 in BUCK class current transformer is:
Io=Iavg*(Ton_s+Ton_p)/Ton_p;
Wherein, Io is output current signal, and Iavg is average current signal, and Ton_s is the diode current flow time signal, and Ton_p is gate-controlled switch ON time signal;
S52 compares output current signal and reference voltage signal, obtains error signal;
The error signal of S6 is carried out the PWM modulation, obtains the control signal of gate-controlled switch current time, with conducting or the shutoff of gate-controlled switch in the control signal control current transformer of gate-controlled switch current time, is a determined value thereby control produces the current transformer output current.
Embodiment 1:
A kind of control circuit of controlling isolated form inverse-excitation type current transformer output current as shown in Figure 5 comprises: the anti-violent change depressor T in integrated circuit A, reference voltage source U, the inverse-excitation type current transformer, the gate-controlled switch Q that inserts the former limit of anti-violent change depressor T and the auxiliary winding Na of anti-violent change depressor T;
Auxiliary winding Na gathers the voltage signal on the transformer in the inverse-excitation type current transformer, output voltage index signal Va;
The first input end of integrated circuit A links to each other with the output of gate-controlled switch Q, and receives the current signal Isw of gate-controlled switch Q;
Second input of integrated circuit A links to each other with the anode of auxiliary winding Na, and receives voltage instruction signal Va;
The 3rd input of integrated circuit A receives the reference voltage signal Vref that reference voltage source U provides; Reference voltage signal Vref also can be chosen in the inside of integrated circuit A and realize;
The output of integrated circuit A links to each other with the control end of gate-controlled switch Q, the control signal Vgs of output gate-controlled switch current time.
As shown in Figure 6, integrated circuit A comprises:
RC filter A1, diode current flow time detection circuit A2, gate-controlled switch ON time testing circuit A3, multiplier A4, error compensation circuit A5 and pulse-width modulation circuit A6:
The input 11 of RC filter A1 is the first input end of integrated circuit A, receives the current signal Isw of gate-controlled switch; The output 1 of RC filter A1 links to each other with the first input end 41 of multiplier A4 and exports average current signal Iavg;
Diode current flow time detection circuit A2 input 21 is second input of integrated circuit A, receives voltage instruction signal Va; The output 2 of diode current flow time detection circuit A2 links to each other with second input 42 of multiplier A4 and output diode ON time signal Ton_s;
The input 31 of gate-controlled switch ON time testing circuit A3 receives the control signal Vgs in a moment on the gate-controlled switch, and the output 3 of gate-controlled switch ON time testing circuit A3 links to each other with the 3rd input 43 of multiplier A4 and exports gate-controlled switch ON time signal Ton_p;
The first input end 41 of multiplier A4 receives average current signal Iavg, and second input, 42 reception diode ON time signal Ton_s, the 3rd input 43 receive output gate-controlled switch ON time signal Ton_p; The output 4 of multiplier A4 links to each other with the first input end 51 of error compensation circuit A5 and exports output current signal Io; The inner computing formula that realizes of multiplier A4 is: Io=Iavg*Ton_s/Ton_p;
The first input end 51 of error compensation circuit A5 receives output current signal Io, and second input 52 is the 3rd input of integrated circuit A, and receives reference voltage signal Vref; The output 5 of error compensation circuit A5 links to each other with the input 61 of pulse-width modulation circuit A6 and output error signal Vea;
The input 61 of pulse-width modulation circuit A6 receives error signal Vea, and output 6 is the output of integrated circuit A, output gate-controlled switch current time control signal Vgs.
RC filter A1 as shown in Figure 7, resistance R is the output 1 of RC filter A1 with the end of connecting of capacitor C, the other end of resistance R is the input 11 of RC filter A1.
Diode current flow time detection circuit A2 as shown in Figure 9 comprises zero cross detection circuit A21 and pulse width detection circuit A22; The anode of comparator B among the zero cross detection circuit A21 is the input 21 of diode current flow time detection circuit A2, receive voltage instruction signal Va, the output output zero current signal ZCD1 of comparator B, zero current signal ZCD1 is exporting zero current detection signal ZCD through rest-set flip-flop F with the output of door G; The output of pulse width detection circuit A22 is the output 2 of diode current flow time detection circuit A2, and the input of pulse width detection circuit A22 receives zero current detection signal ZCD, at output output diode ON time signal Ton_s;
In conjunction with Fig. 8 as can be known, be under the DCM pattern at current working mode, if the discontinuous current time is long, the zero current signal ZCD1 of the output output of comparator B can export a burst pulse It during diode current is zero, this may influence diode current flow time detection circuit A2 and normally detect diode current flow time signal Ton_s; In the present embodiment, as shown in Figure 9, the rest-set flip-flop F that the zero cross detection circuit A21 among the diode current flow time detection circuit A2 comprises has realized that this control circuit can be applicable to CRM, DCM and three kinds of current working modes of CCM simultaneously; Under the DCM pattern, the control signal Vgs in a moment on the gate-controlled switch that the S termination receipts gate-controlled switch inside of rest-set flip-flop F provides, when being implemented in gate-controlled switch Q shutoff, gate-controlled switch control signal Vgs is trailing edge, have only first trailing edge to trigger effectively, with the pulse of shielding back; And under CRM and CCM pattern, there are not the problems referred to above, can select to remove rest-set flip-flop F, the diode current flow time detection circuit A2 that removes rest-set flip-flop F as shown in figure 10, the anode of comparator B among the zero cross detection circuit A21 is the input 21 of diode current flow time detection circuit A2, receive voltage instruction signal Va, that the output of comparator B is exported is zero current detection signal ZCD; The output of pulse width detection circuit A22 is the output 2 of diode current flow time detection circuit A2, and the input of pulse width detection circuit A22 receives zero current detection signal ZCD, and at output output diode ON time signal Ton_s.
A kind of gate-controlled switch ON time testing circuit A3 as shown in figure 11, be a kind of pulse width detection circuit, the input of pulse width detection circuit is the input 31 of gate-controlled switch ON time testing circuit A3, and the output of pulse-width modulation circuit is the output 3 of gate-controlled switch ON time testing circuit A3.
A kind of error compensation circuit A5 as shown in figure 12, comprise comparator B1, wherein the negative terminal of comparator B1 is the first input end 51 of error compensation circuit A5, the anode of comparator B1 is second input 52 of error compensation circuit A5, and the output of comparator B1 is for being the output 5 of error compensation circuit A5.
A kind of pulse-width modulation circuit A6 as shown in figure 13 comprises comparator B2 and rest-set flip-flop F1, and the negative terminal of comparator B2 is the input 61 of pulse-width modulation circuit A6; The R end of rest-set flip-flop F1 connects the output of comparator B2, and the Q end of rest-set flip-flop F1 is the output 6 of pulse-width modulation circuit A6.
The control method of present embodiment control current transformer output current may further comprise the steps:
(1) gathers on the voltage signal, gate-controlled switch of transformer among the current signal Isw, current transformer of gate-controlled switch Q in the current transformer constantly a control signal Vgs, and obtain reference voltage signal Vref;
(2) the switching frequency component among the filtering gate-controlled switch current signal Isw obtains average current signal Iavg;
(3) voltage signal is changed, obtained voltage instruction signal Va; Va detects to voltage instruction signal, obtains diode current flow time signal Ton_s;
Voltage instruction signal Va detected comprise the steps:
(a) voltage instruction signal Va is carried out zero passage detection, obtain zero current detection signal ZCD;
(b) zero current detection signal ZCD is carried out pulsewidth and detect, obtain diode current flow time signal Ton_s;
In the diode current flow time detecting, can adopt the method for simulation to realize, in the present embodiment, utilize zero current detection signal ZCD to control a constant-current source, constant-current source continued an electric capacity is charged in the zero current detection signal ZCD valid period, the voltage of electric capacity is directly proportional with pulse duration, utilizes this magnitude of voltage, obtains diode current flow time signal Ton_s;
More simple mode be with the ZCD signal through a low pass filter (can adopt the circuit structure form with the described RC filter of Fig. 7), obtain its mean value, this mean value is directly proportional with the pulsewidth of ZCD signal, has also embodied the ON time of diode.
(4) the control signal Vgs to a moment on the gate-controlled switch carries out the pulsewidth detection, obtains gate-controlled switch ON time signal Ton_p;
In the gate-controlled switch ON time detects, can adopt the method for simulation to realize, in the present embodiment, utilize the control signal Vgs in a moment on the gate-controlled switch to control a constant-current source, the control signal Vgs valid period in constant-current source moment on gate-controlled switch continues an electric capacity is charged, the voltage of electric capacity is directly proportional with pulse duration, utilizes this magnitude of voltage, obtains gate-controlled switch ON time signal Ton_p;
More simple mode be with the Vgs signal through a low pass filter (can adopt the circuit structure form with the described RC filter of Fig. 7), obtain its mean value, this mean value is directly proportional with the pulsewidth of Vgs signal, has also embodied the ON time of switching tube.
(5) based on average current signal Iavg, diode current flow time signal Ton_s and gate-controlled switch ON time signal Ton_p, calculate output current signal Io;
Wherein, computing formula is:
Io=Iavg*Ton_s/Ton_p;
Output current signal Io and reference voltage signal Vref are compared, obtain error signal Vea;
(6) error signal Vea is carried out the control signal Vgs that the PWM modulation obtains gate-controlled switch Q current time, with conducting or the shutoff of gate-controlled switch Q in the control current transformer, thereby control produces the determined value of current transformer output current.
Embodiment 2:
Other structures of control circuit that a kind of in the present embodiment controls isolated form inverse-excitation type current transformer output current are identical with embodiment 1, as different from Example 1, realize that pulsewidth detects the digitized mode that adopted:
Diode current flow time detection circuit A2 among the integrated circuit A comprises zero cross detection circuit A21 and counter A22, a kind of diode current flow time detection circuit A2 as shown in figure 14, the anode of comparator B among the zero cross detection circuit A21 is the input 21 of diode current flow time detection circuit A2, receive voltage instruction signal Va, the output output zero current signal ZCD1 of comparator B, zero current signal ZCD1 is exporting zero current detection signal ZCD through rest-set flip-flop F with the output of door G; The output of counter A22 is the output 2 of diode current flow time detection circuit A2, and the input of counter A22 receives zero current detection signal ZCD, at output output diode ON time signal Ton_s;
Identical with embodiment 1, the rest-set flip-flop F that the zero cross detection circuit A21 among the diode current flow time detection circuit A2 comprises has realized that this control circuit can be applicable to CRM, DCM and three kinds of current working modes of CCM simultaneously; And under the mode of operation of CRM and CCM, zero cross detection circuit A21 can select to remove rest-set flip-flop F, and diode current flow time detection circuit A2 circuit structure at this moment then as shown in figure 15;
Gate-controlled switch ON time testing circuit A3 among the integrated circuit A as shown in figure 16, is a counter, and the input of counter is the input 31 of gate-controlled switch ON time testing circuit A3, receives the control signal Vgs in a moment on the gate-controlled switch; The output of counter is the output 3 of gate-controlled switch ON time testing circuit A3, output gate-controlled switch ON time signal Ton_p.
The control method of present embodiment control current transformer output current may further comprise the steps:
(1) obtains reference voltage signal Vref, and gather on the voltage signal, gate-controlled switch of transformer among the current signal Isw, current transformer of gate-controlled switch Q in the current transformer constantly a control signal Vgs;
(2) the switching frequency component among the filtering gate-controlled switch current signal Isw obtains average current signal Iavg;
(3) voltage signal is changed, obtained voltage instruction signal Va; Va detects to voltage instruction signal, obtains diode current flow time signal Ton_s;
Voltage instruction signal Va detected comprise the steps:
(a) voltage instruction signal Va is carried out zero passage detection, obtain zero current detection signal ZCD;
(b) zero current detection signal ZCD is carried out pulsewidth and detect, obtain diode current flow time signal Ton_s; In the present embodiment, utilize the pulse duration of counting test zero current detection signal ZCD, obtain diode current flow time signal Ton_s.
(4) the control signal Vgs to a moment on the gate-controlled switch carries out the pulsewidth detection, obtains gate-controlled switch ON time signal Ton_p; In the present embodiment, utilize the pulse duration of the control signal Vgs in a moment on the counting test gate-controlled switch, obtain gate-controlled switch ON time signal Ton_p;
(5) based on average current signal Iavg, diode current flow time signal Ton_s and gate-controlled switch ON time signal Ton_p, calculate output current signal Io,
Wherein, computing formula is:
Io=Iavg*Ton_s/Ton_p;
Output current signal Io and reference voltage signal Vref are compared, obtain error signal Vea;
(6) error signal Vea is carried out the control signal Vgs that the PWM modulation obtains gate-controlled switch Q current time, with conducting or the shutoff of gate-controlled switch Q in the control current transformer, thereby control produces the determined value of current transformer output current.
Embodiment 3:
The control circuit of a kind of control isolated form inverse-excitation type current transformer output current with differential circuit as shown in figure 17 comprises main circuit, integrated circuit A and the reference voltage source U identical with embodiment 1 structure, and present embodiment also comprises a differential circuit Lco; The input of described differential circuit Lco is gathered the voltage signal on winding one end of the former limit of transformer in the inverse-excitation type current transformer, output output voltage index signal Va;
Be the work wave of circuit under CRM, DCM and three kinds of mode of operations of CCM in the present embodiment as shown in figure 18, equally, adopt differential circuit lco as voltage sampling circuit, under the DCM mode of operation, if the discontinuous current time is long, the zero current signal ZCD1 of the output output of the comparator B among the diode current flow time detection circuit A2 among the integrated circuit A also can export a burst pulse It during diode current is zero, this can influence diode current flow time detection circuit A2 equally and normally detect diode current flow time signal Ton_s; Accordingly, in the present embodiment execution mode of diode current flow time detection circuit A2 with consistent described in the embodiment 1.
The method of present embodiment control current transformer output current is with embodiment 1.
Embodiment 4:
A kind of control circuit of controlling BUCK-BOOST current transformer output current as shown in figure 19 comprises: the coupling winding Na of the magnetizing inductance Lo in integrated circuit A, reference voltage source U, the BUCK-BOOST current transformer, gate-controlled switch Q and magnetizing inductance Lo;
Coupling winding Na gathers the voltage signal on the magnetizing inductance Lo in the inverse-excitation type current transformer, output voltage index signal Va;
The first input end of integrated circuit A links to each other with the output of gate-controlled switch Q, and receives the current signal Isw of gate-controlled switch Q;
Second input of integrated circuit A inserts the terminal voltage of magnetizing inductance Lo, receives described voltage instruction signal Va;
The 3rd input of integrated circuit A receives the reference voltage signal Vref that reference voltage source U provides;
The output of integrated circuit A links to each other with the control end of gate-controlled switch Q, the control signal Vgs of output gate-controlled switch current time.
Integrated circuit A structure among the embodiment 4 and relative theory are with embodiment 1.
The method of present embodiment control current transformer output current is with embodiment 1.
Embodiment 5:
A kind of control circuit of controlling non-isolation type BUCK class current transformer output current as shown in figure 20 comprises: the coupling winding Na of the outputting inductance Lo of integrated circuit A, reference voltage source U, current transformer, gate-controlled switch Q and outputting inductance Lo;
Coupling winding Na gathers the voltage signal on the magnetizing inductance Lo in the BUCK class current transformer, output voltage index signal Va;
The first input end of integrated circuit A links to each other with the output of gate-controlled switch Q, and receives the current signal Isw of gate-controlled switch Q;
Second input of integrated circuit A inserts a terminal voltage of the coupling winding of output magnetizing inductance Lo, receives described voltage instruction signal Va;
The 3rd input of integrated circuit A receives the reference voltage signal Vref that reference voltage source U provides; Reference voltage signal Vref also can be chosen in the inside of integrated circuit A and realize;
The output of integrated circuit A links to each other with the control end of gate-controlled switch Q, the control signal Vgs of output gate-controlled switch current time.
As shown in figure 21, integrated circuit A comprises:
RC filter A1, diode current flow time detection circuit A2, gate-controlled switch ON time testing circuit A3, multiplier A4, error compensation circuit A5 and pulse-width modulation circuit A6:
The input 11 of RC filter A1 is the first input end of integrated circuit A, receives the current signal Isw of gate-controlled switch; The output 1 of RC filter A2 links to each other with the first input end 41 of multiplier A4 and exports average current signal Iavg;
Diode current flow time detection circuit A2 input 21 is second input of integrated circuit A, receives voltage instruction signal Va; The output 2 of diode current flow time detection circuit A2 links to each other with second input 42 of multiplier A4 and output diode ON time signal Ton_s;
The input 31 of gate-controlled switch ON time testing circuit A3 receives the control signal Vgs in a moment on the gate-controlled switch, and the output 3 of gate-controlled switch ON time testing circuit A3 links to each other with the 3rd input 43 of multiplier A4 and exports gate-controlled switch ON time signal Ton_p;
The first input end 41 of multiplier A4 receives average current signal Iavg, second input, 42 reception diode ON time signal Ton_s, the 3rd input 43 receives output gate-controlled switch ON time signal Ton_p, and the output 4 of multiplier A4 links to each other with the first input end 51 of error compensation circuit A5 and exports output current signal Io; The inner computing formula that realizes of multiplier A4 is: Io=Iavg*(Ton_s+Ton_p)/and Ton_p;
The first input end 51 of error compensation circuit A5 receives output current signal Io, and second input 52 is for the 3rd input of integrated circuit A and receive a reference voltage signal Vref; The output 5 of error compensation circuit A5 links to each other with the input 61 of pulse-width modulation circuit A6 and output error signal Vea;
The output 61 of pulse-width modulation circuit A6 receives error signal Vea, and output 6 is the output of integrated circuit A, output gate-controlled switch current time control signal Vgs.
Be the work wave under CRM, DCM and three kinds of mode of operations of CCM of present embodiment circuit as shown in figure 22, its wave character is with embodiment 1.In the present embodiment, the particular circuit configurations of described RC filter A1, diode current flow time detection circuit A2, gate-controlled switch ON time testing circuit A3, error compensation circuit A5 and pulse-width modulation circuit A6 is identical with embodiment 1.
The control method of present embodiment control current transformer output current may further comprise the steps:
(1) the control signal Vgs in a moment on the voltage signal of the coupling winding Na that is coupled with outputting inductance Lo in the current signal Isw of gate-controlled switch Q, the current transformer in the collection current transformer, the gate-controlled switch, and obtain reference voltage signal Vref;
(2) the switching frequency component among the filtering gate-controlled switch current signal Isw obtains average current signal Iavg;
(3) voltage signal is changed, obtained voltage instruction signal Va; Va detects to voltage instruction signal, obtains diode current flow time signal Ton_s;
Voltage instruction signal Va detected comprise the steps:
(a) voltage instruction signal Va is carried out zero passage detection, obtain zero current detection signal ZCD;
(b) zero current detection signal ZCD is carried out pulsewidth and detect, obtain diode current flow time signal Ton_s;
(4) the control signal Vgs to a moment on the gate-controlled switch carries out the pulsewidth detection, obtains gate-controlled switch ON time signal Ton_p;
(5) based on average current signal Iavg, diode current flow time signal Ton_s and gate-controlled switch ON time signal Ton_p, calculate output current signal Io,
Wherein, computing formula is:
Io=Iavg*(Ton_s+Ton_p)/Ton_p;
Output current signal Io and reference voltage signal Vref are compared, obtain error signal Vea;
(6) error signal Vea is modulated the control signal Vgs that obtains gate-controlled switch Q current time, with conducting or the shutoff of gate-controlled switch Q in the control current transformer, thereby control produces the current transformer output current value.
Embodiment 6:
Be that the present invention is applied to an a kind of specific embodiment regulating the isolated form flyback power supply of output current based on Triac as shown in figure 23; The Triac light adjusting circuit is used for realizing the adjustable of output current.
Triac light adjusting circuit U1 comprises: Chuan Lian phase-controlled dimmer Tr, electromagnetic interface filter Em and rectifier bridge z successively; Triac light adjusting circuit U1 be used for to receive the current transformer ac input signal, and exports one and have the AC signal at cut angle; Reference voltage modulation circuit U2 is used for lotus root and is connected to described AC signal with cut angle, based on described cut angle signal, exports described reference voltage signal Vref;
In the present embodiment, through Triac light adjusting circuit U1, utilize rectifier bridge with alternating current input power supplying (as common civil power), export a direct current voltage, be applied to described inverse-excitation type current transformer.In embodiment illustrated in fig. 23, electromagnetic interface filter etc. are for preventing that power supply from applying the interference of electrical network, to not influence of concrete enforcement of the present invention.
The Triac light adjusting circuit is controlled by the angle of flow to AC signal, and control is applied to the input voltage of power supply, as shown in figure 25.The cut angle is more big, wishes that output current is more little.Because input voltage is dc pulse moving voltage, usually, the anti-input current that swashs current transformer is also followed the tracks of the waveform signal (realizing so-called PFC control) of input voltage, realizes in the cycle that in a power frequency (line frequency) mean value of output current equates with reference voltage.Therefore, in order to regulate the size of output current, can realize by changing reference voltage signal Vref.Shown in Figure 24, its output current benchmark Vref is directly proportional with the angle of flow, the set point Vref0 when maximum is full conducting, and this will be apparent to those skilled in the art.
All the other implementations, identical with embodiment 1 etc., be not described in detail here.Its PWM modulation system, for realizing the PFC function, therefore, its PWM modulation can be based on methods such as CRM PFC control mode shown in Figure 26 (tape input electric voltage feed forward) or permanent ON time controls.
More than though embodiments of the present invention have been described by reference to the accompanying drawings, those of ordinary skills can make various changes or modification within the scope of the appended claims.

Claims (3)

1. control method of controlling the current transformer output current may further comprise the steps:
(1) obtain reference voltage signal, and gather current signal and last a control signal constantly of gate-controlled switch in the current transformer, and the voltage signal in the current transformer;
(2) the switching frequency component in the described gate-controlled switch current signal of filtering obtains average current signal;
(3) described voltage signal is changed, obtained voltage instruction signal, then described voltage instruction signal is detected, obtain the diode current flow time signal;
(4) based on the control signal in a moment on the gate-controlled switch, obtain gate-controlled switch ON time signal;
(5) based on described average current signal, diode current flow time signal and gate-controlled switch ON time signal, calculate output current signal; Described output current signal and described reference voltage signal are compared, obtain error signal;
The formula that calculates output current signal is:
In the inverse-excitation type current transformer be:
Io=Iavg*Ton_s/Ton_p;
In BUCK class current transformer be:
Io=Iavg*(Ton_s+Ton_p)/Ton_p;
Wherein, Io is output current signal, and Iavg is average current signal, and Ton_s is the diode current flow time signal, and Ton_p is gate-controlled switch ON time signal;
(6) described error signal is modulated the control signal that obtains the gate-controlled switch current time, with conducting or the shutoff of gate-controlled switch in the control current transformer.
2. the control method of control current transformer output current according to claim 1, it is characterized in that: in the described step (3), the process that described voltage instruction signal is detected is: earlier described voltage instruction signal is carried out zero passage detection, obtain the zero current detection signal; Then described zero current detection signal is carried out pulsewidth and detect, obtain the diode current flow time signal.
3. the control method of control current transformer output current according to claim 1 is characterized in that: in the described step (6), described error signal is carried out the control signal that the PWM modulation obtains the gate-controlled switch current time.
CN 201110295481 2011-09-30 2011-09-30 Control method and control circuit for controlling output current of converter Active CN102355136B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 201110295481 CN102355136B (en) 2011-09-30 2011-09-30 Control method and control circuit for controlling output current of converter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 201110295481 CN102355136B (en) 2011-09-30 2011-09-30 Control method and control circuit for controlling output current of converter

Publications (2)

Publication Number Publication Date
CN102355136A CN102355136A (en) 2012-02-15
CN102355136B true CN102355136B (en) 2013-10-02

Family

ID=45578656

Family Applications (1)

Application Number Title Priority Date Filing Date
CN 201110295481 Active CN102355136B (en) 2011-09-30 2011-09-30 Control method and control circuit for controlling output current of converter

Country Status (1)

Country Link
CN (1) CN102355136B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI499181B (en) * 2013-10-25 2015-09-01 Asian Power Devices Inc Can be applied to the power factor correction converter control circuit module

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103730921A (en) * 2013-11-18 2014-04-16 青岛盛嘉信息科技有限公司 Charger
CN105763030B (en) * 2014-12-17 2018-07-13 万国半导体(开曼)股份有限公司 In the circuit and method that electric pressure converter startup stage inhibits electric current excessive
US10862398B2 (en) * 2015-02-03 2020-12-08 Astec International Limited DC-DC power converter for use in data communications distributed power architecture
US20170179834A1 (en) * 2015-12-16 2017-06-22 Richtek Technology Corporation Power converter and switch control module therein
KR102429957B1 (en) * 2017-06-01 2022-08-09 현대자동차주식회사 Controlling method and system for on board charger of vehicle
CN108736706A (en) * 2018-08-01 2018-11-02 杭州老板电器股份有限公司 Controllable switch power supply and purification water tank comprising the power supply
CN109039093B (en) * 2018-09-29 2024-01-23 杰华特微电子股份有限公司 Isolation type switching power supply and control method thereof
CN110190735A (en) * 2019-06-21 2019-08-30 杰华特微电子(杭州)有限公司 Switching Power Supply

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7352595B2 (en) * 2005-11-08 2008-04-01 System General Corp. Primary-side controlled switching regulator
CN101777770A (en) * 2010-02-12 2010-07-14 浙江大学 Control circuit for voltage dropping type power factor corrector
CN101925237A (en) * 2010-08-20 2010-12-22 杭州电子科技大学 Primary constant-current control device of isolated type flyback converter
CN201805600U (en) * 2010-09-30 2011-04-20 杭州电子科技大学 Primary-side constant-current control device of LED driver
CN102186292A (en) * 2011-04-30 2011-09-14 杭州电子科技大学 Primary edge current reference generating circuit and method for high power factor constant-current switch power supply

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7352595B2 (en) * 2005-11-08 2008-04-01 System General Corp. Primary-side controlled switching regulator
CN101777770A (en) * 2010-02-12 2010-07-14 浙江大学 Control circuit for voltage dropping type power factor corrector
CN101925237A (en) * 2010-08-20 2010-12-22 杭州电子科技大学 Primary constant-current control device of isolated type flyback converter
CN201805600U (en) * 2010-09-30 2011-04-20 杭州电子科技大学 Primary-side constant-current control device of LED driver
CN102186292A (en) * 2011-04-30 2011-09-14 杭州电子科技大学 Primary edge current reference generating circuit and method for high power factor constant-current switch power supply

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI499181B (en) * 2013-10-25 2015-09-01 Asian Power Devices Inc Can be applied to the power factor correction converter control circuit module

Also Published As

Publication number Publication date
CN102355136A (en) 2012-02-15

Similar Documents

Publication Publication Date Title
CN102355136B (en) Control method and control circuit for controlling output current of converter
CN205160392U (en) System for an equipment and be used for power conversion for power transistor driver of control power circuit
CN102832836B (en) Cascade boost and inverting buck converter with independent control
CN101925222B (en) Power output circuit for LED driving device
CN202353859U (en) Controllable silicon light regulation device and illuminating system
CN103716965B (en) LED drive device and control circuit thereof and output current detection circuit
CN102769981B (en) Intelligent constant-current driver realized by embedded chip and control method of intelligent constant-current driver
CN102368662A (en) Current reference generation circuit, constant current switch power supply control circuit and control method thereof
CN105991050A (en) Method and device for high-power-factor flyback converter
CN102186292B (en) Primary edge current reference generating circuit and method for high power factor constant-current switch power supply
CN102769960A (en) Dimmable type LED (Light Emitting Diode) driver and control method of dimmable type LED driver
CN104702095B (en) Switching power supply controller and switching power supply comprising switching power supply controller
CN104038045B (en) high power factor correction control circuit and device
CN106169863A (en) The control circuit of buck-boost type circuit of power factor correction and control method thereof
CN104638913B (en) Single-inductance double-output switch converters bicyclic voltage-type PFM control and its device
CN202997938U (en) A high power factor constant current drive circuit and a high power factor constant current device
CN102685982A (en) Primary side feedback constant current control circuit
CN102946196A (en) High-power factor constant-current drive circuit and constant-current device
TW201308842A (en) Buck converter and its control circuit and control method
CN104467433A (en) Method and device for controlling critical continuous mode unit power factor flyback converter
CN204442169U (en) Switch power controller and comprise the Switching Power Supply of this switch power controller
CN106162998B (en) A kind of LED drive controls circuit, control device and control method
CN103648222A (en) Non-isolated field light-emitting diode (LED) driving circuit with power factor corrector (PFC) and controller thereof
CN103547041B (en) Led drive circuit
CN103716952A (en) LED switch power supply and control method thereof

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant